Part 2 of a two-part series.In the last article on this subject in the Maui Weekly, we looked at some of the issues affecting renewable energy technologies, including their intermittent nature and their high initial capital costs. We noted that wave power plants are not mature technologies yet, but costs are expected to drop significantly over time as they have for wind, solar, geothermal and biomass.
If you’re interested in seeing how costs have dropped for other renewable technologies, check out the National Renewable Energy Laboratory’s Energy Analysis Office Website at www.nrel.gov/analysis/docs/cos_curves_2002.ppt. You’ll see, for instance, that the cost of photovoltaic-generated electricity has plummeted from about $1 per kilowatt-hour in 1980 to around $.20 today. There is no data yet for wave power plants.
Wave power has some advantages compared to other renewables. Water is denser than air, meaning that wave energy devices can have higher conversion efficiencies than wind turbines and should take up less space per kilowatt of capacity than either wind or photovoltaics. And, because the waves continue day and night, wave energy conversion machines don’t stop producing, like solar technologies do when the sun goes down.
However, being in the ocean does have some disadvantages. Operating in salt water is challenging; you have corrosion and bio-fouling (such as the growth of algae and corals on equipment) to contend with. The complex ocean ecosystem includes many plant and animal species, some of which are threatened or endangered, and the impact of a wave power plant on these species is not well understood. Storms have damaged wave devices elsewhere in the world, while other companies’ wave demonstrations have suffered leaks or other malfunctions.
The proposed Oceanlinx wave power plants will certainly be a learning experience, though one with great promise. The knowledge gained in Maui waters will be of international interest and will benefit far more people than the lucky residents of the Valley Isle.
In partnership with the state’s energy office, the Maui Weekly provides this feature to help Valley Isle homeowners reduce their utility bills and increase their environmental awareness.